1. Field of the Invention
The present invention relates to an aiming device, and in particular relates to an optical sight.
2. Description of the Related Art
The aiming device is disposed on a firearm to assist aiming of a target. FIG. 1 is cross section of a conventional aiming device 10. The conventional aiming device 10 comprises a housing 101, an objective lens assembly O1, an ocular lens assembly O2, an erector tube assembly 103 and a crosshair 105. The objective lens assembly O1 is disposed on an objective end of the housing 101 while the ocular lens assembly O2 is disposed on an ocular end of the housing 101. The erector tube assembly 103, is disposed in the housing 101 and between the objective end and the ocular end, wherein an upside down image received by the ocular lens is adjusted to a correct position. The crosshair 105 is disposed on an end of the erector tube assembly 103, which is near the ocular end of the housing 101.
FIG. 2 is a front view showing the crosshair 105 of the conventional aiming device 10. The crosshair 105 is formed by two linear lines perpendicularly intersecting with each other, of which a point of aim is formed to focus onto a target. Additionally, the crosshair 105 further comprises several dots A. When shooting at a long ranged target, the dots A may be used to assist the user to compensate for the effect of gravity on the bullet in order to precisely hit the target.